In the present study we examined the effects of capsaicin, a pungent principle of red hot pepper, on mice testes. Capsaicin was injected subcutaneously at a dose of 1 mg/kg body means everyday for a week each time On 21, 35 and 50-day-olds respectively. The body and testes means of all mice comprising the experiment groups were higher than the control groups. The intertubular compartment of the testes in both group mice showed ++ positive reaction with Oil Red O staining. Spermatogenic cell serial formation took place earlier compared to the control group. Our study results indicate that capsaicin is relatively non toxic at this dose (1 mg/kg body means) tested in male mice, no mortality was observed during the study, the experiment groups were hyperactive and spermatogenic series develop earlier.